[PATCH v6 0/4] Fine tune USB 3.0 PHY on exynos5420

From: Vivek Gautam
Date: Tue Sep 02 2014 - 07:12:43 EST

This series is based on Heikki's patches for simpliefied phy lookup table:
[PATCHv3 0/6] phy: simplified phy lookup [1], applied against 'usb-next' branch
alongwith Sergei's patch for adding generic phy support to usb hcd [2].

NOTE: We need to get above dependencies merged first in order to merge this
As of now patches @ [1] are posted with all the comments addressed
and we are waiting for an ACK on them, but
patch @ [2] needs to be re-spined as Sergie says in [3]:
"Yes, I'm planning this since Greg has lost v4."

Changes since v5:
- Assigned NULL to hcd->gen_phy in error path in xhci-plat.c, so that
we don't need to check for IS_ERR() while calibrating the PHYs in
- Removed extra empty lines in register definitions in exynos5-usbdrd
phy driver.
- Added write access for EXYNOS5_DRD_PHYREG0 register before any
crport_handshake() call as suggested by Jingoo Han.
- Renamed member 'calibrate' to 'phy_exynos_calibrate' of
struct exynos5_usbdrd_phy_drvdata.

Changes since v4:
- Rebased on latest patches by Heikki.
- Took care of handling -EPROBE_DEFER error number while getting PHY in
xhci plat.

Changes from v3:
- Modified error message as per review comments from Julius.

Changes since v2:
- Removed any check for DWC3 in xhci-plat for getting usb2-phy and usb3-phy,
in order to make it more generic.
- Moved the phy_calibration calls to core/hcd.c to enable a more generic
solution for issues of calibrating the PHYs.

Changes since v1:
- Using 'gen_phy' member of 'hcd' instead of declaring more variables
to hold phys.
- Added a check for compatible match for 'Synopsys-dwc3' controller,
since the 'gen_phy' member of 'hcd' already gets the 'usb' PHY
in core/hcd.c; but XHCI on Synopsys-dwc3 doesn't need that,
instead two separate PHYs for UTMI+ and PIPE3 for the two HCDs
(main hcd and shared hcd).
- Restructured the code in 'xhci_plat_setup()' and 'xhci_plat_resume()'
to use hcd->gen_phy directly. Also added the check for Synopsys's DWC3
controller while trying to calibrate the PHY.

Explanation for the need of this patch-series:
"The DWC3-exynos eXtensible host controller present on Exynos5420/5800
SoCs is quirky. The PHY serving this controller operates at High-Speed
by default, so it detects even Super-speed devices as high-speed ones.
Certain PHY parameters like Tx LOS levels and Boost levels need to be
calibrated further post initialization of xHCI controller, to get
SuperSpeed operations working."

[1] https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg710094.html
[2] http://comments.gmane.org/gmane.linux.ports.sh.devel/35932
[3] http://www.spinics.net/lists/linux-usb/msg112300.html

Vivek Gautam (4):
phy: Add provision for calibrating phy.
usb: host: xhci-plat: Get PHYs for xhci's hcds
usb: hcd: Calibrate PHY post hcd reset
phy: exynos5-usbdrd: Calibrate LOS levels for exynos5420/5800

drivers/phy/phy-core.c | 36 ++++++++
drivers/phy/phy-exynos5-usbdrd.c | 185 ++++++++++++++++++++++++++++++++++----
drivers/usb/core/hcd.c | 18 ++++
drivers/usb/host/xhci-plat.c | 27 ++++++
include/linux/phy/phy.h | 8 ++
5 files changed, 259 insertions(+), 15 deletions(-)


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